The Speed Energy series features 600-plus horsepower “Super Stadium” trucks running at speeds up to 130 mph on serpentine race courses set up in open stadiums or using existing road or street circuits. The courses include ramps that can launch the trucks 20 feet in the air.

The new agreement means all competitors will run on street-legal Toyo Open Country A/T II tires. Last year, in the series’ inaugural season, Toyo was the tiresupplier to series organizer Robby Gordon and a few other selected competitors.

Amy Coleman, Toyo’s senior director of marketing, said winning the Stadium Super Truck championship last year with Mr. Gordon proved that the Open Country tires “are up to the task of being the spec tire of this exciting series.”

Mr. Gordon noted that Open Country tires used in the Speed Energy series are the same tires he uses for the off-road vehicles he races in the Dakar Rally and Baja 1000.

The 2014 Speed Energy Formula Off-Road series features 13 races at several venues, including high-profile events like the Indianapolis 500, the 2014 X Games in Austin, Texas, and the Sand Sports Super Show in Orange County, Calif.

Three events already have taken place — two races at St. Petersburg, Fla., and one at Long Beach, Calif., as support races during the IndyCar Series weekends at those venues. Twelve events are scheduled to be televised on NBC Sports Network or ABC/ESPN.

Mr. Gordon is a former NASCAR and IndyCar driver who is also an off-road champion and long-time Team Toyo driver.